Apple on Thursday made available an update to OS X Mountain Lion v10.8.3 through its software update mechanism, fixing 21 vulnerabilities, with most actively been exploited in the wild to execute malicious codes.

The security update follows series of patches for Java flaw which led to the attacks on notable companies.

The zero-day Java flaw led to compromise on Mac OS X computers belonging to Apple as well, of which the company released an official acknowledgement. The company warned concerning Java Web Start application been run at the background, even when Java plug-in has been deactivated.

Mac OS X Mountain Lion update can be downloaded from the Apple Software Update page. The v10.8.3 update is recommended to all users of OS X Mountain Lion as it includes fixes and features aimed at improving stability, compatibility and security of your machine.

The company have made available an extensive tutorial about the update in a release note, detailing procedures to follow in installing the Mac OS X update.